Terraform shell provider

This is a terraform provider that lets you wrap shell based tools to Terraform resources in a simple way.

There is also exec provider, but it only implements Create CRUD operation.

Naming

The naming of this provider has been hard. The provider is about wrapping functionality by running shell scripts. Originally the name was generic_shell_wrapper, but currently the name is just shell. The naming in code is still inconsistent.

Installing

Copied from the Terraform documentation:

To install a plugin, put the binary somewhere on your filesystem, then configure Terraform to be able to find it. The configuration where plugins are defined is ~/.terraformrc for Unix-like systems and %APPDATA%/terraform.rc for Windows.

Build it from source (instructions below) and move the binary terraform-provider-shell to bin/ and it should work.

Using the provider

First, an simple example that is used in tests too

provider "shell" {
  create_command = "echo \"hi\" > test_file"
  read_command = "awk '{print \"out=\" $0}' test_file"
  delete_command = "rm test_file"
}

resource "shell_resource" "test" {
}

$ terraform plan
$ terraform apply
$ terraform destroy

To create a more complete example add this to the sample example file

provider "shell" {
   alias = "write_to_file"
   create_command = "echo \"%s\" > %s"
   create_parameters = [ "input", "file" ]
   read_command = "awk '{print \"out=\" $0}' %s"
   read_parameters = [ "file" ]
   delete_command = "rm %s"
   delete_parameters = [ "file" ]
}

resource "shell_resource" "filetest" {
  provider = "shell.write_to_file"
  arguments {
    input = "this to the file"
    file = "test_file2"
  }
}

Parameters can by used to change the resources.

Building from source

1. Install Go on your machine
2. Set up Gopath
3. git clone this repository into $GOPATH/src/github.com/toddnni/terraform-provider-shell
4. Get the dependencies. Run go get
5. make install. You will now find the binary at $GOPATH/bin/terraform-provider-shell.

Running acceptance tests

make test

Known Problems

• The provider won't support Update CRUD operation.
• The provider won't print output of the commands.
• The provider will error instead of removing the resource if the delete command fails. However, this is a safe default.
• Changes in provider do not issue resource rebuilds. Please parametrize all parameters that will change.

Author

• Toni Ylenius

The structure is inspired from the Softlayer and libvirt Terraform provider sources.

Some code has been adapted from local-exec provisioner from terraform core.

License

• MIT, See LICENSE file